much smaller ring file, UI tweaks

css/base.css

@@ -1612,6 +1612,7 @@ img.channel {
   background-color: #eee;
   border-radius: 0.5rem;
   border: 2px solid #ccc;
+  overflow: hidden;
 }
 
 .video-elem:hover {

src/views/incoming-call-view.jsx

@@ -12,7 +12,7 @@ import { CALL_STATE_INCOMING_RECEIVED } from '../constants.js';
 import { makeImageUrl } from '../lib/blob-helpers.js';
 import { clipStr } from '../lib/utils.js'
 
-const RING_SOUND = new Audio('audio/phone_ring.mp3');
+const RING_SOUND = new Audio('audio/call-in.mp3');
 
 export default class IncomingCallView extends React.Component {
   constructor(props) {

umd/index.dev.js

@@ -4401,7 +4401,7 @@ __webpack_require__.r(__webpack_exports__);
 
 
 
-const RING_SOUND = new Audio('audio/phone_ring.mp3');
+const RING_SOUND = new Audio('audio/call-in.mp3');
 class IncomingCallView extends (react__WEBPACK_IMPORTED_MODULE_0___default().Component) {
   constructor(props) {
     super(props);